ShinyProxy and Google authentication Error 404

Question

I can't make work ShinyProxy work with Google authentication because after login I get Error 404:

application.yml (don't worry about secret key, I made it public for tests only):

proxy:
  port: 8080
  authentication: social
  admin-groups: admins
  users:
  - name: jack
    password: password
    groups: admins
  - name: jeff
    password: password
  social:
    google:
      app-id: 81901800067-1sgai4r40a3opihnn9r2n7o0gai6141h.apps.googleusercontent.com
      app-secret: 6-UDqDby1i7Cjd-Xe3-gNtcK
  docker:
      internal-networking: true
  specs:
  - id: 01_hello
    display-name: Hello Application
    description: Application which demonstrates the basics of a Shiny app
    container-cmd: ["R", "-e", "shinyproxy::run_01_hello()"]
    container-image: openanalytics/shinyproxy-demo
    container-network: sp-example-net
  - id: 06_tabsets
    container-cmd: ["R", "-e", "shinyproxy::run_06_tabsets()"]
    container-image: openanalytics/shinyproxy-demo
    container-network: sp-example-net

logging:
  file:
    shinyproxy.log

My github fork: https://github.com/Tazovsky/shinyproxy-config-examples/tree/google-aouth-error-404/02-containerized-docker-engine

Google credentials settings:

To reproduce error run:

docker run --rm -d --name proxy-error -p 8081:8080 kfoltynski/shinyproxy-demo:google-aouth-error-404

Any ideas why it doesn't work?